Automatic air brake



Nov. 11 1924.y

A. SILVENE AUTOMATIC AIR BRAKE Filed March 51 192:5

Patented Nov. ll, i924.

`ANTONY SILVENE, or vicroiain, Biiifrisri COLUMBIA,

CANADA.

Y AUTOMATIC AIB, Seann.

`rip'piieaiifm inea ivrarcn ai, 1923. seiai No; 629,162.

Z0 aZZwwm it may concern:

Beit known thaty l, ANTONY SiLviiNr., citizen of the Dominion of Canada, residing atfVi'ctoria'-, lin the Province of British Coliiinbia, Canada, have linvented certain newV and useful improvements in ,Automatic Air Brakes7 of which the following is a specification.

L This invention relates to anautoinatic air brake which is designed to dispense with the customary triple valve which controls the deliveryl *ofl air from the auxiliary reservoir t the brake cylinder and from the brake cylinder to the atmosphere as the pressure of the train pipe is reduced-or restored It'is'of that class wherein air under pressure is normallyr maintainedV in the train pipe and o 'n both sides ofthe piston of the brake cylinder and inthe auxiliary reservoiraof each vehicle of a train7 and ythe bralze isappliedby a reduction of pressure inthe train pipe and inthe, space of -thecylinder onmone side of the (piston, whereby the air ony the l'other side ofthe-piston, which is'in communication with vthe auxiliary reservoir, expands to move the piston outward land apply the brake. Y e

"The-invention is oarticiilarly described in the followingspecication, reference being made to thedravvings by which it is accompanied', in Which z` Fig. llfis a longitudinal section of the brake cylinder and the auxiliaryreservoir.

YFig- 2 is a similarvieivshoiving a inodr ication vof the smaller piston, and.

Figxf isa longitudinalfsection of a supplementaryairexhaust valve. f

Fig.` i' is a modification in Whichthe cyl inder, covergis recessed into the cylinder.-

u In these dra-Wings 2y represents the brake cylinder, to the after endof which is secured an auxiliary reservoir Bin full `communicationwitli the end of the cylinder to which it is connected. To vtheopposite or forward endof the cylinder 2 is secured acovei' Ll from Which` a cylinder 5 projects in axial alignment With 2. v'This cylinder 5 is of relatively smaller diameter than the b ialre cylinder 2 and its length approximately corresponds therewith.

The cover ofthe cylinder Il has an annular projection'Within the diameter of the cylindei"5,fin the outer side of which projection is seateda leather or bre Washer 6.

er piston Sis endwise movableivithin the cylinder 2 having a pistonrod v9 'secured on its inner end, Which piston is- Provided with two oppositelyturned cupped leathery packing ringsv lO. A piston ll 'is 'secured on the rod at suchdistancefrom the piston 8 that Wliendthat piston isgat the inner limit of yits movement toward the reservoir 3.a lf'shaped annular projection 12 on the piston il Will seat on the Washer `6.

Every care shonldbe taken toj'malre its piston l1 air-tight, preferably, as shown in Fig. 2,' with a cupped leather i3 and a packing ringr l4.

l5 of the cylinder a coiled spring 16 'is introduced that ivillnormally maintainr the pistons 8 and llA at the inner limit of their movement;- as shown inlligs; l and 2` Air is delivered into the forward end of the cylinder 2 from the train Apipe 2O through a branch pipe 2liX connected to the cover lofthatcylinder. The pressure of this air acting:` onthe area Aof the rpiston 8 will inove that.'` piston iand its connected parts to the inner limit of itsniovernent and Will Withdravvthe bralzebloclis from the Wheels of the vehicle. y y

Y Attlie inner limit ofthe baclUvar-diorrelease movement of the piston S the air passes througha feed groove 22 provided past the piston inthe bore 'ofthe cylinder and charges the auxiliary reservoir.

lf the brake is vapplied to avfreightcar, Where there isliable to be any considerable difference between the Weight loaded land empty, orto an exceptionally heavy vehicle, a secondary reservoir 23 maybe provi d to which the' air passes from thef reservoir 3 through a pipe 24 and stop-cock` 25.

When the, train pipe 20 is chargedwith air under vpressure from the main reservoir on the engine, as -when the train is running, the trainpipe20, being in `direct communication With the cylinder 2 and reservoir 3, that air pressure is also maintained en both sides of the piston 8 in the brake cylinder 2 and also in the auxiliary reservoir 37 and in the secondary reservoir 23, if such 'is provided, but is prevented passing into'the cylinder by the seatof the annular V-sliaped ridge of the piston ll on the lerdfher or fibre Washer .i

`When the pressure in the train pipe 2O is Between the piston ll andthe end cover ico reduced either by its release through the drivers brake valve on the engine, or through separation of the couplings of the train pipe, as in the case of a break-away, the air is withdrawn from the forward side of the piston 8 in the cylinder 2 and the air of the auxiliary reservoir, expanding into the cylinder 2 on the other side of the piston 8, that piston is moved outward to apply the brake, with a pressure, dependent on the re` duction made in the train pipe and the volumeof the pistons movement in the cylinder 2 in relation to the volume of the reservoir 3, acting on the available area of the piston 8.

When the pressure in the train pipe 20 is restored, that pressure, acting on the front side of the piston 8, moves it to the backward limit of its movement, returning the air to the auxiliary reservoir 3 and restoring its pressure through the groove 22, and seating the piston 1l. on the washer 6.

To enable the air within the cylinder 2 in front of the piston S to escape more quickly, as when an emergency stop is required, a cup piston 26, endwise movable within a small cylinder 27, is introduced in the branch pipe 2l, through which communication is made from the train pipe- 20 to the cylinder This cup piston has a central aperture 28 through which air may pass to or from the cylinder 2, and the piston is held by a spring 29 at the inner limit of its movement toward the cylinder 2 covering exhaust ports 3() in the body of the cylinder 27.

Air may pass freely from the train pipe 20 to the cylinder 2 through the aperture 28 of the cup piston, and during moderate rc duction of pressure in the train pipe may pass outward from the cylinder through the same aperture, but if a sudden reduction of pressure is made in the train pipe 20, as for an ordinary stop, the air being unable to escape from the forward end of 4the cylinder 2 with suiiici-ent freedom, the cup piston 26 will move outward against the resistance of the spring 29, and will uncover' the ports 30 to provide free escape of the air from the cylinder.

The vseveral parts of this brake are simple and not liable to derangement, and in applying the brake a reduction of pressure in the train pipe will more directly be a measure of the pressure on the several pistons, and will not be subject to the erratic actions which the well known triple valve .is subject to.

Figure 4 shows a modification wherein the cover is recessed into the end of an existing cylinder. i

Having now particularly described my invention, I hereby declare that what I claim as new and desire to be protected in by Letters Patent, is:

l. An automatic air brake, comprising the combination with a brake cylinder, an auxiliary reservoir connected to one end of the cylinder to be in direct communication therewith, a cover on the opposite end of the brake cylinder, a piston endwise movable in the brake cylinder, a rod connected to the piston and passing axially through the cover, a spring` normally holding the piston of the brake cylinder at the backward limit of its movement therein toward the reservoir, means on the piston rod for air sealing it on the cover when the piston of the brake cylinder is at the backward limit of its movement therein, means for delivering air directly from the train pipe to` the forward end of the brake cylinder, and means for passing air from the forward side of the piston to the opposite side'of the same.

2. An automatic air brake, comprising the combination with a brake cylinder, an auxiliary reservoir connected to one end of the brake cylinder to be in direct communication therewith, a cover on the opposite end of the cylinder, said cover having a cylinder of relatively less diameter than the brake cylinder and approximately the same length projecting outwardly from it in axial' alignment with the brake cylinder with an inwardly projecting collar between it and the brake cylinder, a piston endwise movable in the brake cylinder, a piston endwise movable in the cover cylinder', a rod axially connecting the two pistons and projecting through the end of the cover cylinder, means normally holding the pistons at the back ward limit of their movement `toward the reservoir with the piston of the cover cylinder seated air-tight on the collar between the two cylinders, means for delivering air directly from the train pipev to the forward end of the brake cylinder, and means for passing air from the forward side of the piston of the brake cylinder to the reservoir side of the saine when the piston is at the backward limit of its movement.

An automatic air brake, comprising the combination, with a brake cylinder, an auxiliary reservoir connected to Aone end Vof the brake cylinder to be in direct communi-V cation therewith, a cover on the opposite end of the cylinder, said cover having a cylinder of relatively less diameter than the brake cylinder and approximately the same length projecting outwardly from it in axial alignment with .the brakfe cylinder with an inwardly projecting collar ybetween it and the brake cylinder, a piston endwise movable in the brake cylinder, a piston endwise movable in the cover cylinder, a rod axially connecting the two pistons and projecting through the end of the cover cylinder, means normally holding the pistons at the backward limit of their movement toward the reservoir with the piston lllf of the cover cylinder seated air-tight on the collar between the two Cylinders, means for delivering air directly from the trainv pipe to the forward end of the brake cylinder.

d means for passing' air from the forward side of the piston iof the brake cylinder to the reservoir side of the same when the piston is at the backward limit of its movement, and means in the train pipe connection for exhausting air from the brake Cylinder when the pressure of the air is reduced in the train pipe.

In testimony whereof I afX my signature.

ANTONY SILVENE. 

